At COP21¹ which took place in Paris, France, in 2015, the Paris Agreement was adopted with the aim of reducing GHG emissions and other goals. This led to global attention on green hydrogen, but Asahi Kasei had already started developing the alkaline water electrolyzer for producing green hydrogen in 2010.
Our company already had the core technology of industrial electrolysis that we had cultivated through the chlor-alkali electrolysis business, but the development of the alkaline water electrolyzer was uncharted territory. Yousuke Uchino, who led the development from the beginning as an engineer, reflects on his expectations and concerns at that time.
“I majored in chemistry in university and joined Asahi Kasei, aspiring to leverage my knowledge and contribute to society. After an increase in GHG was identified as a cause of global warming at the IPCC² in 2007, I became more eager to make a contribution, particularly in the area of climate change mitigation. I expressed my wish to work on the development of the alkaline water electrolyzer. When my participation in the project was decided, I was thrilled at the new challenge. At the same time, I was also concerned because the project was not within my area of expertise, and we lacked the necessary infrastructure.”

Before Uchino joined the development of the alkaline water electrolyzer, he spent a few years working in technical sales of electronic components. To proceed with the development, it was necessary to establish and expand the required infrastructure from scratch. Uchino’s skills in communication and coordination, cultivated in his previous work, proved invaluable during internal negotiations. He built cooperative relationships among R&D sites in Kawasaki, Nobeoka, Fuji, and Mizushima, consolidating technical expertise, know-how, and infrastructure to accelerate the development. In 2013, only two and a half years into the development, the project team developed a medium-sized demonstration plant, which served as a prototype for the current large-scale alkaline water electrolyzer. In 2015, they were entrusted with a project by NEDO³ and focused their efforts on creating a larger system and accumulating 12,000 hours of operating time on a large-scale demonstration plant of 100 kW. They also had a demonstration plant adopted in the h2herten⁴ project in Herten, North Rhine-Westphalia, Germany. These achievements were evaluated by NEDO, and Asahi Kasei's Aqualyzer™ alkaline water electrolysis system was selected for a new NEDO project⁵ at the Fukushima Hydrogen Energy Research Field (FH2R), constructed in Namie Town, Fukushima Prefecture. This involved designing and developing a 10 MW-class⁶ alkaline water electrolyzer, one of the world’s largest. Following construction and test operation, the system began full-scale operation in 2020.

Going around Namie Town, you can sense the dawn of a hydrogen society. In this town, hydrogen was introduced as an energy source at various locations, such as mobile hydrogen stations and a pure hydrogen fuel cell system implemented at the rest stop. Along the coast, you can see the FH2R with its eye-catching solar panels.

In this NEDO project, the purpose of operating FH2R is to demonstrate a hydrogen energy system utilizing 20 MW of electricity generated from renewable sources. Asahi Kasei was selected to demonstrate the electricity conversion efficiency, long-term reliability, and responsiveness to renewable energy fluctuations and grid demand of a 10 MW-class alkaline water electrolyzer for hydrogen production.
The highest technical hurdle in hydrogen production using an alkaline water electrolyzer is responding to fluctuations in electricity generated from renewable sources. Conventional alkaline water electrolyzers had problems such as slow response to electricity fluctuations, limited flexibility in start-stop cycles, and a narrow range of manageable power variations, so it was considered to be a difficult challenge to use such a system with fluctuating renewable energy sources. The main reasons for these problems were believed to be the deterioration of electrical efficiency that generally occurs with repeated starts and stops, and damage to structural components resulting from changes in the internal fluid conditions as a result of electricity fluctuations. Therefore, Asahi Kasei developed fundamental technologies for responding to fluctuations, such as robust components capable of withstanding repeated starts and stops, protective circuitry to mitigate component degradation, and technology for stabilizing the internal fluid. By leveraging these technologies, we succeeded in developing a large-scale alkaline water electrolyzer that can produce green hydrogen over the long term, thereby meeting the expectations of the NEDO project.

In this way, the three-year demonstration operation at FH2R finished successfully, and the AqualyzerTM alkaline water electrolyzer took a big step toward the realization of a hydrogen society.
"The 10 MW-class alkaline water electrolyzer, which was nearly two orders of magnitude larger than previous demonstration plants, presented an extreme challenge. As one of the engineers involved in the analysis of equipment and components, I wanted to perform inspection and evaluation more frequently since I anticipated the need for some debugging in order to achieve stable operations. However, the NEDO project at FH2R involved many stakeholders, and hydrogen production couldn’t be easily suspended, partly due to high demand periods for hydrogen. The demonstration period was also limited, and we needed to conduct maintenance within short timeframes. After going through a trial-and-error process to overcome these restrictions, we utilized digital twin technology and big data analysis to improve technical capabilities for preventive maintenance. As a result, we were able to forecast potential problems in advance, and achieved stable operation.”
In technology management, transitioning from research to product development is sometimes referred to as crossing a “Devil River,” and moving from product development to commercialization is navigating a “Valley of Death.” Looking back, Uchino describes the demonstration at FH2R as a “Valley of Death” full of many obstacles, where failure could potentially close off the path to commercialization.

Following the demonstration at FH2R, Asahi Kasei is currently accelerating its efforts to commercialize the large-scale alkaline water electrolyzer for producing green hydrogen by 2025. Drawing on the expertise and know-how gained at FH2R, Asahi Kasei is actively working on improving electrolysis performance and reducing costs of the water electrolysis system. In addition to the system, the company is developing a total solution package that includes remote monitoring for operating management and preventive maintenance, data-driven management services, and maintenance services for long-term support.
The realization of a hydrogen society also necessitates further external collaborations. Nobuko Uetake, Head of the Green Solution Project, says:
“The hydrogen business requires the creation of a new supply chain for production, transportation, and consumption in cooperation with many companies, such as upstream energy providers, midstream hydrogen transportation and storage companies, and downstream hydrogen consumers. Fortunately, we have received many inquiries about our Aqualyzer™ large-scale alkaline water electrolyzer, so we would like to consider the optimal partnering while playing a leading role in building a supply chain. Our future goal is to become a leading supplier of water electrolysis systems, making it a new pillar of business by 2030.”

Energy is essential for humankind. It influences various aspects of our society, including mobility (trucks, buses, railways, ships, and aircraft), industry (including chemicals, mining, and construction), and our daily lives. In a hydrogen society, hydrogen will replace traditional energy sources. But the future is unpredictable, as there are numerous issues to address and hurdles to overcome. It is inspiring to learn of the enthusiasm of members involved as they describe their roles and future prospects. The goal of transforming the world with our green hydrogen production technology to create a sustainable society, along with the sense of steady progress toward that future, serve as the driving force that motivates everyone involved in the hydrogen business.